[PATCH v2 0/2] sparc64: Recover from userspace non-resumable PIO & MEM errors

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



A non-resumable errors from userspace is able to cause kernel panics or trap
loops due to the setup and handling of the queued traps once in the kernel.
This patch series addresses both of these issues.

The queues are fixed by simply zeroing the memory before use.

PIO errors from userspace will result in a SIGBUS being sent to the user
process.

The MEM errors form userspace will result in a SIGKILL and also cause the
offending pages to be claimed so they are no longer used in future tasks.
SIGKILL is used to ensure that the process does not try to coredump and result
in an attempt to read the memory again from within kernel space.  Although
there is a HV call to scrub the memory (mem_scrub), there is no easy way to
guarantee that the real memory address(es) are not used by other tasks.
Clearing the error with mem_scrub would zero the memory and cause the other
processes to proceed with bad data.

The handling of other non-resumable errors remain unchanged and will cause a
panic.

Liam R. Howlett (2):
  sparc64: Zero pages on allocation for mondo and error queues.
  sparc64: Handle PIO & MEM non-resumable errors.

 arch/sparc/kernel/irq_64.c   |  2 +-
 arch/sparc/kernel/traps_64.c | 74 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+), 1 deletion(-)

-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe sparclinux" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Kernel Development]     [DCCP]     [Linux ARM Development]     [Linux]     [Photo]     [Yosemite Help]     [Linux ARM Kernel]     [Linux SCSI]     [Linux x86_64]     [Linux Hams]

  Powered by Linux